Let President Barack Obama leave office with a remarkable international trade accomplishment, and it's not just his legacy that will be amended and made shiny, but the American economy that may then stand and shout with a smile on its face for years to come. So why not do it?

Here's why not. Because there are special interests such as labor unions out there trying to serve a narrow good by defeating the public good. Because there are politicians who kowtow to them for the sake of votes. Because there are extremist-instructed versions of reality that are unreal. Because there are Democrats.

And there they were this week: Democrats, outrageously, pathetically, demagogically unifying in the Senate to block a vote on fast-track trade legislation that would then facilitate passage of a pact known as the Trans-Pacific Partnership that just maybe could work wonders for us and others.

There was, it should be said, one disagreeing Senate Democrat who voted with the GOP  one!  and another disagreeing Democrat in the White House. He had met with Democratic senators, begged them for support, promised them much of what they said they wanted and criticized them in public. Maybe, to get them to go along, he should have reverted to his teeth-bared, unilateralist style and, as a quid pro quo, issued an executive order keeping them in office as long as they like.

Pardon the exaggeration, but it speaks to a chief reason Republicans have been fretting about fast track. They see it as one more instance of Obama stretching his power too far, only this time they are off-key. Fast-track, which lets the executive branch negotiate and has Congress then vote up or down for a trade treaty without amendment or filibuster, is not unilateralism. Congress is part of the action. It can say "no" and more, in this legislation, if a deal is defeated. Repeatedly in the past, presidents have operated under the fast-track mode and it has paid off handsomely.

The Democratic objections are mostly of a different order, although some do fear abuse if a Republican were president. They say, for instance, that the expedited Pacific deal would cost American workers jobs just as past treaties supposedly have done, and does not do enough to protect against mistreatment of workers abroad. They say they are worried about foreign currency manipulation that makes it harder to sell U.S. exports.

Some quick answers:

First, honest trade pacts, and especially the Pacific one with 11 partners, can lead to far more wealth and job-creating expansion and benefits for most of us  including low-price imports that save low-income Americans literally billions of dollars at such retailers as Wal-Mart  than business as usual. Agriculture would get an enormous boost, as would large numbers of manufacturers.

As Philip Levy of the American Enterprise Institute has pointed out, it is hooey that the Clinton-era North Atlantic Trade Agreement led to far fewer jobs, if any fewer. Trade deals can cause some dislocations, but, the Senate fast track bill is accompanied by a measure helping those Americans who do suffer unemployment thanks to trade. And analysts note we already have mechanisms in place to address actual currency manipulation.

Second, the Obama administration has wedded agreements about treatment of foreign labor into the Pacific deal. Keep in mind, however, that underdeveloped countries can never treat labor as well as it is treated in developed countries until they become developed themselves. And they cannot become developed if the partner in a trade agreement demands undoable correctives mainly for the purpose of mothering special interests at home through giving them less competition.

At this dismaying point, keep in mind a couple of encouraging items, first that one battle alone does not win a campaign and second that Republican Senate Majority Leader Mitch McConnell is a persistent, determined, tough if practically conciliatory customer who will almost surely be back on this issue again, and win.